The lock idea just isn't.. amazing. What you COULD do is like make some other characters that can talk (get to that later) and they could make some kind of lock-oriented jokes at him... but you'd have to be a funny guy to think of funny jokes having to do with LOCKS.
Second, you need voices. Or at least download a more realistic voice simulator than what you have. There are free ones out there.
Last, draw more detailed backgrounds. Your backgrounds were black and white. And consisted of a single line.